JP2001040873A - Void pipe - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a void pipe which can be smoothly taken out from the concrete surface after solidification and reused after mold release. SOLUTION: A void pipe 1 for building a hollow portion by erecting to a form 2 for forming concrete is a hard hollow pipe core member 3 fixed to the form 2 and a cylindrical shape externally inserted to the hollow pipe core member 3 and a mold release layer 4a having releasability from concrete is formed at least on the outer surface, and its inner surface comprises an outer surface of the hollow pipe core member 3 and a freely deformable flexible cylinder 4 forming a mold release surface 4b having the mold releasability.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a void tube constructed on a formwork for forming concrete to form a hollow portion. More specifically, the present invention relates to a method for pouring a concrete between opposed formworks and solidifying the same. The present invention relates to a void tube which can be deformed, easily peeled off from concrete, and used repeatedly.

[0002]

2. Description of the Related Art When building walls, ceilings, floors, and the like with concrete, it is widely used in construction sites to provide hollows for pipes and the like. Here, the hollow portion is a through-hole penetrating the concrete, and is formed by using a paper cylinder called a void tube.

[0003] The procedure for constructing the above-mentioned hollow portion using a void tube will be described below, taking as an example the case where a vertical wall is constructed of concrete.

FIG. 7 is an exploded perspective view showing a conventional void tube.

[0005] First, a space in which a concrete is molded is surrounded by opposing molds 102, and a void tube 101 is provided between the molds 102 and 102 at a position where a hollow portion is formed by a nail, a gum tape or the like. And is supported by the temporary fixing member.

In recent years, as shown in FIG. 7, there is a so-called void cap 103 for supporting and fixing both ends of the above-mentioned void tube 101. In addition, the void tube 101 is fixed to the mold frame 102 and supported by the formwork 102.

[0007] Here, a reinforcing bar (not shown) for maintaining strength is fixed to the form 102 by avoiding the position where the void tube 101 is erected.
Is built in.

Next, ready-mixed concrete is poured between the molds 102,102.

After solidification of the ready-mixed concrete, the form 1
When 02 is removed, the end face 101a of the void tube 101 is exposed.

Here, the void pipe 101 penetrates the concrete wall, and its outer surface is adhered to the concrete.

Next, a sharp tool, for example, a driver
End face 101a of void tube 101 exposing the tip and the like
Then, the driver is inserted into the boundary between the concrete K and the void tube 101, the driver is pressed inward (inward in the radial direction), and the void tube is partially deformed at the open end thereof so that the void tube is interposed between the concrete and the concrete. A gap is formed, and thereafter the gap is enlarged (that is, the void tube is sequentially deformed inward), and the void tube is peeled off from the concrete to form a hollow portion.

Although the above-mentioned void pipe 101 has strength, it is basically made of paper. Therefore, the void pipe 101 is crushed sequentially from its end face in the longitudinal direction while being deformed, and the void pipe 101 is peeled off from concrete to form a hollow pipe. A part may be formed.

In any case, the void tube 101 once deformed or crushed cannot be reused and is discarded.

Although not found in the prior art, a person skilled in the art will appreciate that the outer surface of the void tube 101 may be a release layer having releasability, or that the outer surface of the void tube 101 may be separated from the outer surface of the void tube. It is considered possible to imagine a void tube 101 in which a release agent is integrally formed by applying and adhering a mold agent.

That is, in the case of the void tube 101 having the release layer 110 on the outer surface, if the void tube 101 is pulled out or pushed in the longitudinal direction, it can be smoothly released from concrete. The idea of conceiving the technical idea that the hollow portion can be easily formed without deforming the void tube itself is considered to be equivalent to the prior art.

[0016]

FIG. 8 is a partially enlarged sectional view showing a contact state between concrete and a void tube having a release layer on the outer surface.

The void tube 101 having the release layer 110 integrally formed on the outer surface theoretically appears to be easily released from the concrete K. However, actually, it cannot be easily released from the concrete k. The applicant has made a prototype of this, and has conducted experiments to confirm that the mold cannot be easily released.

It is considered that the cause is in the process of solidifying the concrete k. That is, the ready-mixed concrete filled in the mold 101 is a fluid, and in this state, comes into contact with the outer surface 110a of the release layer 110 of the void pipe 101.

On the other hand, when viewed microscopically, the outer surface 110a is not completely flush but is formed as an uneven surface as shown in FIG. This is even more so when the release layer 110 is applied and adhered.

When the fresh concrete is cast, the void tube 101 may be deformed inward due to the external pressure. In this case, the irregularities are apparent.

For this reason, the present inventor has considered that even if the void tube is pulled out or pushed in the longitudinal direction, the void tube cannot be released smoothly due to the resistance of the uneven surface.

Further, if the release layer has a mirror-finished surface so that the above-mentioned uneven surface is not formed, it may be theoretically possible to perform drawing or the like, but at present, such a release layer does not exist. However, even if a mirror finish can be obtained, the processing becomes extremely expensive and is not suitable for use in a void tube.

In conclusion, the release layer cannot be released smoothly even if the release layer is pulled in the sliding direction with respect to the concrete surface (that is, the longitudinal direction of the void tube) and the pressing force is increased. However, the mold cannot be released smoothly unless it is in a direction substantially perpendicular to the concrete surface (that is, inward of the void pipe in the radial direction).

Therefore, even in the case of the void tube 101 integrally formed with the release layer, the void tube itself must be deformed and destroyed as described above in order to perform the release. 101 could not be reused.

An object of the present invention is to provide a void pipe which can be smoothly and easily released from a concrete surface after solidification, and which can be reused after release. provide.

[0026]

In order to solve the above-mentioned problems, a void pipe according to claim 1 is a void pipe constructed on a formwork for forming concrete to form a hollow portion,
A hard hollow pipe core material fixed to the metal formwork,
A tubular layer extrapolated to the hollow pipe core material, on at least an outer surface of which a release layer having releasability from concrete is formed, and an inner surface of the outer surface of the hollow pipe core material And a deformable flexible cylinder formed with a release surface having releasability.

In the first aspect, the hard hollow pipe and the flexible cylinder having a release layer on at least the outer surface and having a release surface on the inner surface thereof are completely constituted by separate members. Has a first feature.

The second feature is that the flexible tube is made of a material which can be deformed and can be restored at least into a cylindrical shape.

The hard hollow pipe is meant to include the conventional paper void pipe itself.

A void tube according to a second aspect of the present invention is a void tube constructed on a formwork for forming concrete to form a hollow portion, and is a rigid tube constructed on a pair of void caps fixed to the formwork. A hollow pipe core, and a deformable flexible cylinder having a mold release layer having a mold releasability from concrete at least on the outer surface of the cylinder, which is extrapolated into the hollow pipe core. ing.

According to a second aspect, in addition to the first aspect, a void cap is a constituent feature.

Here, the void cap is a known member which is a kind of a fixture interposed between the hollow pipe and the mold so as to bridge the hollow pipe on the mold.

According to a third aspect of the present invention, in the void tube according to the first or second aspect, an elastic cylinder is interposed between the hollow pipe core material and the flexible cylinder. It is formed on the release surface.

According to a third aspect of the present invention, in order to prevent the core material of the hollow pipe from being deformed by the external pressure of the concrete casting, an elastic cylindrical body in which a cushioning material such as styrene foam or urethane foam is formed in a tubular shape is interposed. The inner surface of the elastic cylinder is formed on the release surface.

[0035] The void tube according to claim 4 is characterized in that:
In any one of the above, the hollow pipe core is magnetically or screwed to a mold or a void cap.

According to the fourth aspect, the hollow pipe can be easily installed by magnetically attaching the hollow pipe to the mold or the void cap with a magnet or by screwing the hollow pipe with a screw.

[0037]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is an exploded perspective view showing an embodiment of a void pipe according to the present invention, and FIG. 2 is an exploded sectional view of FIG. 1. This void pipe 1 is installed on a mold 2 for forming concrete. A hard hollow pipe core material 3 fixed to the formwork 2 and a tubular shape externally inserted into the hollow pipe core material 3, and at least an outer surface A deformable flexible cylinder 4 having a release layer 4a having releasability from concrete and a release surface 4b having releasability from the outer surface of the hollow pipe core material 3 on the inner surface. And more.

As shown in FIG. 1, the hollow pipe core material 3 is fixed to the form 2 by a temporary fixing member 51 such as a nail.
Can be fixed facing each other and connected to the void caps 5 and 5. Alternatively, as shown in another embodiment of FIG. 3, a magnet ring 31 is provided at both ends of the hollow pipe core material 3.
If this is magnetically attached to the inner surface of the metal mold 2, it can be easily attached with one touch. Further, although not shown, screw portions are formed at both ends of the hollow pipe 3,
The screw groove portion to be screwed into this screw portion is
It is also possible to form it.

Whether the void cap 5 is used or not is appropriately determined according to the working condition. In any case, the hollow pipe 3 is supported between the molds 2 and 2. Are the same in terms of erection.

The hollow pipe 3 may be a conventional void pipe itself.

The flexible cylinder 4 has at least an outer surface formed with a release layer 4a having releasability from concrete, and an inner surface having releasability from the outer surface of the hollow pipe core material 3. Having a release surface 4b.

The release layer 4a is desirably made of a material having releasability, such as polyethylene, polyethylene, or polypropylene, but it is preferable that the surface of the rubber base material be coated with a resin such as Teflon or silicon. Is also possible.

Similarly, the release surface 4b only needs to have releasability from the outer surface of the hollow pipe 3, and the material of the release layer 4a can be basically used in common.

The flexible tube 4 thus formed is
In addition to the above characteristics, it is a condition that it is deformable and can be formed at least in a cylindrical shape.

For example, in addition to the above-mentioned materials, a material obtained by impregnating a releasable material into a soft non-woven fabric, for example, can be considered. Can not.

The void pipe 1 constructed as described above is constructed in the following manner.

FIGS. 4 (a) to 4 (d) and FIGS. 5 (e) to 5 (h)
FIG. 2 is an explanatory cross-sectional view showing a procedure for constructing a void pipe according to the present invention. Here, a case where a hollow portion as a horizontal pipe hole is formed in a vertical concrete surface is illustrated.

First, one mold 2 is attached and fixed in a predetermined manner, and the void cap 5 is fixed to a predesigned position of the mold 2 with a temporary fixing member 51 such as a nail [FIG. )
reference〕.

Next, one end of the flexible tube 4 is fitted into the void cap 5. Since the flexible tube 4 is a flexible material, its formability is weak. 3 [FIG. 4 (b),
(C)). The flexible pipe 4 may be attached to the void cap 5 while the hollow pipe core 3 is inserted in advance.

At the other end of the flexible cylinder 4, another void cap 5 is fitted, and this void cap 5 is positioned at a previously designed position. 1 is supported and erected between the molds 2 and 2 (see FIG. 4D).

A reinforcing bar (not shown) is provided between the molds 2 and 2 so as to avoid the void tube 1.

The fresh concrete is filled from above to the space between the molds 2 and 2 thus constructed, and the fresh concrete is beaten from the outside of the mold 2 with a gavel or the like, so that the fresh concrete is firmly poured into every corner. [See FIG. 5 (e)].

After a lapse of a predetermined time, the ready-mixed concrete is solidified. When the concrete is completely converted into concrete, the molds 2 and 2 are separated from the outside and removed. At this time,
The void pipes 5 and 5 fixed to the molds 2 and 2 are also removed together, and the void pipe 1 is buried in the concrete K. [See FIG. 5 (f)].

Hereinafter, the procedure for removing the void tube 1 will be described in detail.

First, the hollow pipe core material 3 is pulled out or pushed in from one end of the void pipe 1. The method of pushing and pulling is performed as usual.

The outer surface of the hollow pipe core member 3 can be smoothly removed because it has a releasability from the inner surface 4b of the flexible tube 4 from which it is extrapolated [FIG.
(G)).

Thus, only the flexible tube 4 remains.

If one end of the flexible tube 4 is peeled off in a direction substantially perpendicular to the concrete surface (ie, inward in the radial direction of the void tube), the flexible tube 4 is smoothly separated from the concrete surface. Can be typed.

Thereafter, if the flexible tube 4 is peeled inward in the radial direction of the void tube 1 in order, the entire flexible tube 4 can be released from the concrete K. A hollow portion T can be formed at the same time (see FIG. 5 (h)).

The released flexible cylinder 4 and hollow pipe core material 3 are reused as the void tube 1 in another mold.

FIG. 6 is an exploded perspective view showing another embodiment of the void tube according to the present invention. The void tube 1 has an elastic cylinder 6 formed of a cushioning material such as polystyrene foam or urethane foam between the hollow pipe core 3 and the flexible cylinder 4. The surface has the same releasability as the release surface 4b.

In the void tube 1 provided with the elastic cylinder 6,
This prevents the hollow pipe core material 3 from being deformed by the external pressure of concrete casting. That is, concrete K
The elastic cylinder 6 internally absorbs the pressure from the side, and the inner surface 4b of the elastic cylinder 6 and the outer surface of the hollow pipe core material 3
The generation of unevenness is prevented. Therefore, when the void pipe 1 is constructed, when the hollow pipe core material 3 is pulled out or pushed in as shown in FIG. 5 (g), the outer surface of the hollow pipe core material 3 Has the releasability from the inner surface 4b of the elastic cylindrical body 6 which is extrapolated, and is flush with the inner surface 4b, so that the hollow pipe core material 3 can be more smoothly extracted [see FIG. 5 (g)]. .

[0064]

As described above, according to the void pipe according to the present invention, a rigid hollow pipe, a flexible cylinder having a release layer on at least the outer surface, and having a release surface on the inner surface. Are completely formed of separate members, and the flexible cylinder is formed so as to be freely deformable.

Therefore, the hollow pipe core material after forming the hollow portion can be smoothly pulled out or pushed out from the flexible cylinder without coming into contact with the concrete surface.

Further, if the hollow pipe core is extrapolated by the elastic cylinder, the joint surface between the two is flush, so that the operation of pulling out the hollow pipe core can be performed more smoothly.

After being taken out, the deformable flexible tube can be peeled off in a direction substantially perpendicular to the concrete surface (that is, inward of the void tube in the radial direction), so that the tube can be smoothly removed. The flexible cylinder can be released from the concrete surface.

Further, these flexible tubes and hollow pipes can be reused as other void tubes.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view showing one embodiment of a void tube according to the present invention.

FIG. 2 is an exploded sectional view showing one embodiment of a void tube according to the present invention.

FIG. 3 is an exploded sectional view showing another embodiment of the void tube according to the present invention.

4 (a) to 4 (d) are cross-sectional explanatory views showing a procedure for installing a void pipe according to the present invention.

FIGS. 5 (e) to 5 (h) are cross-sectional explanatory views showing a procedure for constructing a void pipe according to the present invention.

FIG. 6 is an exploded perspective view showing another embodiment of the void tube according to the present invention.

FIG. 7 is an exploded perspective view showing a conventional void tube.

FIG. 8 is a partially enlarged cross-sectional view showing a contact state between a void pipe having a release layer on the outer surface and concrete.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Void tube 2 Form frame 3 Hollow pipe core material 31 Magnet ring 4 Flexible cylinder 4a Release layer 4b Release surface 5 Void cap

Claims (4)

[Claims] 1. A void pipe constructed on a mold forming concrete to form a hollow portion, comprising: a hard hollow pipe core fixed to the metal mold; and a hollow pipe core attached to the hollow pipe core. It is a cylindrical shape to be inserted, on at least the outer surface of which a release layer having releasability from concrete is formed, and on the inner surface thereof, a release layer having releasability from the outer surface of the hollow pipe core material. A void tube consisting of a deformable flexible cylinder with a mold surface and a deformable tube. 2. A void tube for constructing a hollow portion by laying on a formwork for forming concrete, comprising: a hard hollow pipe core material laid on a pair of void caps fixed to the formwork; It is a tubular shape that is extrapolated to the hollow pipe core material, and has a mold release layer having releasability from concrete on at least the outer surface, and has an inner surface that is separated from the outer surface of the hollow pipe core material. A void tube comprising a deformable flexible cylinder having a mold release surface and a deformable flexible cylinder. 3. An elastic cylinder according to claim 1, wherein an elastic cylinder is interposed between the hollow pipe core and the flexible cylinder, and an inner surface of the elastic cylinder is formed on the release surface. Void tube. 4. The void pipe according to claim 1, wherein the hollow pipe core is magnetically or screwed to a mold or a void cap.